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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *   http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing,
13   * software distributed under the License is distributed on an
14   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   * KIND, either express or implied.  See the License for the
16   * specific language governing permissions and limitations
17   * under the License.
18   */
19  package org.apache.maven.settings.building;
20  
21  import java.io.PrintWriter;
22  import java.io.StringWriter;
23  import java.util.ArrayList;
24  import java.util.List;
25  
26  /**
27   * Signals one ore more errors during settings building. The settings builder tries to collect as many problems as
28   * possible before eventually failing to provide callers with rich error information. Use {@link #getProblems()} to
29   * query the details of the failure.
30   *
31   * @author Benjamin Bentmann
32   */
33  public class SettingsBuildingException extends Exception {
34  
35      private final List<SettingsProblem> problems;
36  
37      /**
38       * Creates a new exception with the specified problems.
39       *
40       * @param problems The problems that cause this exception, may be {@code null}.
41       */
42      public SettingsBuildingException(List<SettingsProblem> problems) {
43          super(toMessage(problems));
44  
45          this.problems = new ArrayList<>();
46          if (problems != null) {
47              this.problems.addAll(problems);
48          }
49      }
50  
51      /**
52       * Gets the problems that caused this exception.
53       *
54       * @return The problems that caused this exception, never {@code null}.
55       */
56      public List<SettingsProblem> getProblems() {
57          return problems;
58      }
59  
60      private static String toMessage(List<SettingsProblem> problems) {
61          StringWriter buffer = new StringWriter(1024);
62  
63          PrintWriter writer = new PrintWriter(buffer);
64  
65          writer.print(problems.size());
66          writer.print((problems.size() == 1) ? " problem was " : " problems were ");
67          writer.print("encountered while building the effective settings");
68          writer.println();
69  
70          for (SettingsProblem problem : problems) {
71              writer.print("[");
72              writer.print(problem.getSeverity());
73              writer.print("] ");
74              writer.print(problem.getMessage());
75              String location = problem.getLocation();
76              if (!location.isEmpty()) {
77                  writer.print(" @ ");
78                  writer.println(location);
79              }
80          }
81  
82          return buffer.toString();
83      }
84  }